Lincity is a freeware open source city simulation game. You are required to build and maintain a city. You must feed, house, provide jobs and goods for your residents. You can build a sustainable economy with the help of renewable energy and recycling, or you can go for broke and build rockets to escape from a pollution ridden and resource starved planet, it's up to you.

The download and install go easy. But I did not find the game all that fun. I have played a LOT of SIM City. The interface is different, although the grid and road system concept remains the same. If you have played SIM City, the strategy is a bit different, since you start out at a much older level of technology. And you can run your funds deep deep deep into a hole. It almost seemed like the People's republic of SIM City....